The present invention is related to the field of data communications networks, and more particularly to networks providing transparent local area network (LAN) service.
Wide-area data communications networks or WANs can be used to provide so-called “transparent LAN service” among devices attached to geographically separated LAN segments. Transparent LAN service effectively hides the underlying WAN network from the devices, and thus enables the devices to communicate using only their native LAN protocol. Transparent LAN service can provide several important benefits such as backwards compatibility while providing fast connection speeds and lower operating costs. Newer WAN networking equipment can successfully interoperate with devices having only LAN interfaces, and customer investments in LAN equipment can be protected, easing customer acceptance of newer networking technology.
Transparent LAN service has been provided for different types of LANs in different types of WANs. Ethernet is one of the predominant LAN technologies, and therefore is widely supported in various implementations of transparent LAN service. Transparent LAN service has been provided in circuit-based WANs such as ATM and frame relay networks.
In a connection oriented WAN such as a frame relay network, transparent LAN service requires potentially numerous point-to-point connections among LAN clients on different LAN segments attached to the frame relay network. The required connectivity can be expensive and difficult to configure and maintain. In particular, it can be cumbersome to accurately specify the respective rates at which data is expected to be transferred between each of many source/destination pairs, a function that is required in the provisioning of frame relay and other data circuits. It would be desirable for transparent LAN services to be provided in a simpler manner so as to reduce the costs and complexity involved in configuring and otherwise managing enterprise networks that rely on transparent LAN services